环境科学最新文献

{"title":"[Impact of Alpine Wetland Succession to Soil Bacterial Diversity].","authors":"Ri-Na Dao, Ying Zhang, Xi-Lai Li, Qiang Li, Lin-Xiong Ma, Xiao-Long Tie","doi":"10.13227/j.hjkx.202403266","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403266","url":null,"abstract":"<p><p>This study aims to explore the characteristics of change and the rules of response of the soil bacterial community structure and diversity during the evolution of alpine wetlands. It also seeks to identify the leading factors affecting changes in the soil bacterial community, with the goal of providing a scientific basis for the restoration and management of alpine wetland ecosystems. Three different types of wetlands （original alpine wetland, alpine wet meadow, and alpine meadow） were selected to represent the succession process of alpine wetlands. The composition and diversity of the soil bacterial communities were analyzed using high-throughput sequencing technology. The findings revealed the following： ① Proteobacteria and Acidobacteria were the predominant bacteria, with their relative abundance exceeding 20.08%. In the alpine wetland, Nitrosomonadaceae and <i>RB41</i> were the dominant bacteria. Meanwhile, Chthoniobacteraceae and <i>Candidatus_Udaeobacter</i> were the dominant genera in the alpine wet meadow and alpine meadow, respectively. ② Although no significant change was observed in community diversity, significant differences were present in the structure of the soil bacterial community at different succession stages （<i>P</i>&lt;0.05）. ③ Metabolism was a core function. ④ The Mantel test and Pearson correlation analysis indicated that soil pH and total phosphorus （TP） content were the primary factors influencing soil bacterial diversity throughout the succession process of alpine wetlands. During the process of reversed succession in alpine wetlands, changes in soil pH and nutrient content occur, and these changes collectively influence the structure and diversity of the soil bacterial community.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1897-1904"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Spatio-temporal Variation, Meteorological Condition, and Regional Transport Characteristics of PM_2.5 Pollution Events in Beijing from 2018 to 2022].","authors":"Yuan-Xi Guo, Bao-Xian Liu, Yun-Ting Li, Xiu-E Shen, Shu-Xiao Wang, Qian Song, Chen Chen, Feng Sun, Yang Chen, Rui-Wen Sun, Qian Li, De-Jia Yin, Yue-Qi Jiang, Zhao-Xin Dong","doi":"10.13227/j.hjkx.202403173","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403173","url":null,"abstract":"<p><p>Based on PM_2.5 monitoring data, meteorological observation data, and a CMAQ-ISAM air quality model, the spatio-temporal variation, meteorological conditions, and regional transport characteristics of 108 PM_2.5 pollution events in Beijing from 2018 to 2022 were analyzed. The results showed that the frequency, the mean concentration, and the peak concentration of PM_2.5 pollution events demonstrated a significant decrease and the decrease degree of moderate and heavy pollution events was significantly larger than that of light pollution events. From the seasonal perspective, the PM_2.5 pollution events nearly disappeared in summer, however, were severe in other seasons. According to the diurnal variation curves, PM_2.5 concentration during heavy pollution events decreased significantly from daytime to the first half of night and did not decrease notably in the second half of the night. In the past five years, the mean concentration of PM_2.5 pollution events was higher in the southeast and lower in the northwest, with the highest in the Beijing Economic and Technological Development Area and the lowest in Yanqing District. From the perspective of spatial evolution, the mean concentration in all districts significantly decreased from 2018 to 2022, with a decrease range of 13-31 μg·m^-3 and a decrease percentage of 11%-25%； the frequency in all districts also decreased significantly, with a decrease range of 35-52 days and a decrease percentage of 56%-68%. The mean wind speed, mean relative humidity, and northwest wind frequency were the three most important meteorological factors that had an impact on PM_2.5 concentration in Beijing. For polluted days, the mean wind speed was 1.6 m·s^-1, the mean relative humidity was 62.4%, and the frequency of northwest wind was 3%. Most of the pollution events began from Eastern Beijing and Southern Beijing. Compared to those throughout the whole city, PM_2.5 pollution events usually occurred 12 hours earlier at the southeast border station and 10, 8, and 5 hours earlier at the southern, southwest, and eastern border stations, respectively. During PM_2.5 pollution events in Beijing, the local contribution was 34%, and the transport contribution was 66%. Out of all nearby provinces, Hebei had the biggest contribution of 33%. With regard to cities, Baoding, Langfang, Tianjin, and Tangshan had the most prominent impact on Beijing's PM_2.5 pollution events, accounting for 9%, 6%, 5%, and 5% of the contribution, respectively. When it comes to transport pathways, the southeast pathway contributed 24% and the southwest pathway contributed 23%. The government must establish a regional joint prevention and control mechanism.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1265-1274"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Multi-scenario Energy Consumption and Carbon Emission Prediction in Tianjin Based on LEAP Model].","authors":"Bao-Zhu Li, Ya-Jie Liu, Shao-Cong Zhang","doi":"10.13227/j.hjkx.202403081","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403081","url":null,"abstract":"<p><p>The carbon peaking and carbon neutrality goals require China to reduce energy consumption and reduce carbon emissions. Taking Tianjin as an example, the carbon emission inventory was compiled, and the driving degree of each factor was identified by the logarithmic mean index method （LMDI）. Based on this, combined with scenario analysis, the LEAP-TJ model was constructed to explore the trend of terminal energy consumption and carbon emission in Tianjin from 2022 to 2060. The results showed that the economic scale was the first leading factor for the growth of terminal carbon emissions in Tianjin. Energy consumption and carbon emissions will continue to increase in the baseline scenario, and carbon emissions in 2060 will be 2.7 times those in 2021. Under the comprehensive scenario, Tianjin will realize the terminal peak carbon dioxide emissions in 2025, and its carbon emissions will be reduced by 85.1% compared with those under the baseline scenario in 2060, with a remarkable carbon emission reduction effect.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1492-1501"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Pollution Characteristics and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Urban Shanghai].","authors":"Jiong Tu, Ying-Ge Ma, Hai-Xia Dai, Xin-Wei Feng, Yu-Hang Wu, Rui-Miao Di, Li-Ping Qiao, Min Zhou, Zhang-Fa Tong","doi":"10.13227/j.hjkx.202403105","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403105","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Polycyclic aromatic hydrocarbons （PAHs） and their derivatives, nitrated polycyclic aromatic hydrocarbons （NPAHs） and oxygenated polycyclic aromatic hydrocarbons （OPAHs）, have been under constant scrutiny for their prominent carcinogenicity and mutagenicity. In this study, fine particulate matter （PM&lt;sub&gt;2.5&lt;/sub&gt;） was collected in the urban area of Shanghai from 2022 to 2023. Their diurnal and nocturnal mass concentration variations, sources, and health risk assessment were analyzed. Two-dimensional gas chromatography-time-of-flight mass spectrometry （GC×GC-ToF-MS） was used to quantify PAHs, NPAHs, and OPAHs. The results showed that the daily average concentrations of PAHs, NPAHs, and OPAHs were 4.44, 0.89, and 2.38 ng·m&lt;sup&gt;-3&lt;/sup&gt;, respectively, in winter. The concentration levels were much lower in summer than those in winter, which were 0.20, 0.04, and 0.40 ng·m&lt;sup&gt;-3&lt;/sup&gt;, respectively. The ratio of the concentrations of NPAHs to those of PAHs and OPAHs concentrations by 1-2 orders of magnitude. The substance concentrations of PAHs and NPAHs in summer were higher in the daytime than those at nighttime and vice versa for OPAHs. Concentrations of the few target substances in winter samples were higher at night. The substances with the highest concentrations of PAHs during the sampling period were fluoranthene and benzo（b）fluoranthene, whereas the substances with the highest concentrations of NPAHs and OPAHs were 9-nitroanthracene and 9,10-anthraquinone, respectively. Based on the results of correlation analysis and source analysis by the diagnostic ratios, PAHs and their derivatives in PM&lt;sub&gt;2.5&lt;/sub&gt; in the urban area of Shanghai were affected by mixed emission sources, with primary emissions accounting for a significant portion. In addition to vehicle emissions and some coal and biomass combustion, the generation of PAHs was also affected by aerosol aging. Vehicle emissions were the major source of NPAHs, whereas OPAHs might be from the same primary emission sources as those of PAHs. Primary emissions contributed more to PAHs in winter than in summer. Comparison of the toxic equivalents of PAHs, NPAHs, and OPAHs in PM&lt;sub&gt;2.5&lt;/sub&gt; in winter and summer during the sampling period revealed that the average daily TEQ value was higher in winter （441.4 pg·m&lt;sup&gt;-3&lt;/sup&gt;） than that in summer （39.8 pg·m&lt;sup&gt;-3&lt;/sup&gt;）, which was consistent with the seasonal variation of mass concentrations. The toxicity of PAHs and their derivatives in PM&lt;sub&gt;2.5&lt;/sub&gt; in the Shanghai urban area was higher during nighttime than that in the daytime. Most of the potential carcinogenic risk originated from PAHs, and the ILCR values caused by NPAHs and OPAHs were 1-2 orders of magnitude lower than those caused by PAHs. The results of health risk assessment based on incremental lifetime cancer risk modeling showed that the total cancer risk was higher in adults than that in adolescents and children and that females had a higher cancer risk than males through di","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1326-1339"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Spatial Differentiation Characteristics and Driving Factors of Soil Organic Carbon in Various Landscape Complexes].","authors":"Chen-Chen Kong, Fang Yan, Wei-Rui Wang, Shi-Wen Zhang, Dan-Dan Guo, Shan Wang","doi":"10.13227/j.hjkx.202403253","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403253","url":null,"abstract":"<p><p>Investigating the spatial differentiation characteristics of soil organic carbon （SOC） in regional agricultural land and analyzing its driving factors are important for screening auxiliary variables for SOC prediction in agricultural land and the accurate prediction of soil carbon stock. This study considered SOC in different types of agricultural land landscape complexes in Beijing as the research object. The differences in SOC content and its stock in different landscape complexes were explored based on the long-term positional monitoring data on the quality of cultivated land in Beijing and the field sampling and testing data. Utilizing multi-source and open-source data as environmental variables that affected SOC spatial differentiation, we explored the quantitative and spatial relationships between SOC and climate, topography, soil parent material, land use, and biomass factors in different landscape complexes through GeoDetector and geographically weighted regression modeling. Additionally, we constructed a structural equation model to reveal the pathways that influence each driving factor on SOC in terms of direct and indirect effects. Ultimately, the major controlling factors of SOC were identified in the study area. The results showed that： ① The mean values of <i>ω</i>（SOC） for various types of landscape complexes in the study area ranged from 6.23 to 28.26 g·kg^-1, with a variation coefficient of 3.80% to 33.92%, showing spatial heterogeneity. ② Climate, topography, soil parent material, land type, and biomass factors contributed to SOC at highly significant levels （<i>P</i> &lt; 0.01）, and all factors were synergistic on SOC after their interaction. All factors could explain the spatial variation of SOC from 0.691 to 0.704, with stable explanatory validity. ③ Temperature, topography, and land type showed a highly significant direct effect （<i>P</i> &lt; 0.01） on SOC in the study area. Among them, temperature was negatively correlated with SOC content. In different land types, SOC content was higher in landscape complexes located in forested land and lower in cultivated land. Topographic factors had the most excellent direct effect on SOC （effect value = 0.698, <i>P</i> &lt; 0.001）, with higher SOC content in the mountains and lower in the plains, and topographic factors could also exert an indirect effect on SOC through differences in temperature and land type （<i>P</i> &lt; 0.01）. Soil parent material and normalized difference vegetation index correlated significantly with topographic factors but had non-significant （<i>P</i> ≥ 0.05） direct effects on SOC content. Overall, topographic factors are essential factors influencing SOC spatial heterogeneity in the study area. It can be used as a critical cofactor to provide a reference for accurately assessing soil carbon stock on agricultural land in the study area.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1679-1689"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Cd Enrichment Characteristics and Bioavailability of Soil-crops in the Migration Type Geological High Background Area of Poyang Lake, Jiangxi Province].","authors":"Bang-Yong Wen, Hai-Man Qie, Yuan Gao, Hong-Yu Jiang, Qiang-Qiang Zhou","doi":"10.13227/j.hjkx.202401002","DOIUrl":"https://doi.org/10.13227/j.hjkx.202401002","url":null,"abstract":"<p><p>To study the accumulation characteristics and bioavailability of Cd in the soil-crop system in the migration type geologically high background area, 140 groups of crops and soil samples were collected from the Jiulong area on the south bank of Poyang Lake. The results showed that the range of <i>ω</i>（Cd） of root soil was 0.03-0.65 mg·kg^-1, with an average of 0.16 mg·kg^-1, which exceeded the background value of soil in Jiangxi Province, reflecting the characteristics of high geological background of migration type. The over-standard rate of Cd in root soil was 6.43%, which was slightly polluted. Sesame had the strongest enrichment ability of Cd （404%）, followed by that of peanut （146%）. The enrichment ability of rice, <i>Camellia oleifera</i>, and Euryale seed was medium, while that of corn was weak. The root soil <i>ω</i>（active Cd） was 76.8 μg·kg^-1, and the bioavailability was 48.9%, among which rice was the highest with 98.6 μg·kg^-1 and 59.9%, respectively. Principal component analysis （PCA） showed that root soil Cd was mainly caused by the transport and accumulation of industrial and mineral pollutants in the upstream, reflecting the characteristics of the high geological background of the transport type. Correlation showed that the active and bioavailable Cd of root soil were mainly controlled by genetic sources, indicating that the activity of exogenously imported Cd was higher, and the ecological risk was higher.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1774-1782"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Evaluation of Dual Emission Control Effects and Green Innovation Mechanisms: Evidence Based on the Construction of Free Trade Pilot Zones].","authors":"Shao-Lin Li, Dong-Xu Shao, Han-Yi Xue","doi":"10.13227/j.hjkx.202404021","DOIUrl":"https://doi.org/10.13227/j.hjkx.202404021","url":null,"abstract":"<p><p>With the replication and promotion of the experience of pilot reform and innovation, as well as the continuous deepening of institutional openness, exploring green and low-carbon models has become an important measure for the country to promote the high-quality development of free trade pilot zones. This study focused on the core task of institutional innovation in free trade pilot zones, measured and quantified the level of green investment liberalization and green trade facilitation in each region, and explored the carbon emission dual control effect of free trade pilot zones using cutting-edge methods, such as group period average processing effect estimation （CATT）, imputation, and stacked DID. The research conclusions were as follows： ① The phased establishment of free trade pilot zones reduced the total carbon emissions by 27.40% and the carbon emission intensity by 14.30%. ② The pilot free trade zone achieved dual carbon emission control through the spillover effect of green innovation from foreign investment, the direct effect of green innovation from local enterprises, and the indirect effect of green innovation from digital trade. The comprehensive implementation of the negative list of market access, the signing and implementation of free trade agreements between China and other countries, and the increase of international green trade barriers have all had a significant positive regulatory effect on the dual control of carbon emissions in free trade pilot zones. The dual control effect of carbon emissions in the free trade pilot zone exhibited significant spatial spillover characteristics, showing maximum efficiency within a radius of 550 km, resulting in a reduction of 18.30% in the total carbon emissions of surrounding cities and a decrease of 10.10% in carbon emission intensity. Heterogeneity analysis showed that regions with higher levels of institutional innovation and government function transformation had a 13.10% and 13.70% higher total carbon emission control effect compared to that of regions with lower levels and a 8.40% and 3.40% higher carbon emission intensity control effect, respectively. The total carbon emission control effect of cities along the \"Belt and Road\" was 9.60% higher than that of cities not along the line, and the carbon emission intensity was 8.80% higher. The total carbon emission control effect of cities that had opened the China Europe freight train was 16.80% higher than that of cities that had not opened it, and the carbon emission intensity was 7.50% higher. In terms of aligning with international economic and trade rules and achieving high-quality development, the free trade pilot zone should focus on the green and low-carbon qualification review of newly registered foreign-funded enterprises entering and the first attempt to break through technical barriers to green trade, to help carbon emission dual control process of China with high-level openness and coordination.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1558-1572"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Data-driven Analysis on the Spatio-temporal Characteristics and Influencing Factors of Carbon Emissions in Guangdong Province].","authors":"Yi-Ming Ke, Yuan Gao, Ming Yuan, Wei Liu, Fang-Tong Liu","doi":"10.13227/j.hjkx.202403060","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403060","url":null,"abstract":"<p><p>Scientific analysis of carbon emission characteristics is a key link for precise policy implementation and orderly achievement of Carbon Peak and Carbon Neutrality. Taking 21 prefecture level cities in Guangdong Province as research objects, data including their economic activity, energy consumption, and population distribution from 2013 to 2022 was collected. First, the carbon emission accounting method was used to analyze the time changes and spatial distribution characteristics of carbon emissions in the past decade. Second, the principal component analysis and K-means method was used to reduce the dimensionality and cluster division for Guangdong urban characteristics. Third, the Generalized Schur Decomposition model was applied to analyze the influencing factors. Furthermore, carbon reduction strategies for four typical cities in Guangdong Province were proposed. The results showed that： ① From 2013 to 2022, the total carbon emissions in Guangdong Province continued to increase and showed a significant regional imbalance in its spatial distribution. The carbon emissions contribution in the Pearl River Delta region was as high as 42.50%, whereas that in northern Guangdong was the lowest. ② Each city in Guangdong Province performed differently in green development, economic development, and industrial development. All 21 cities could be broadly divided into four categories, namely, Demonstration City, Resource-dependent City, Traditional Industrial City, and Emission-reducing City, accounting for approximately 14.29%, 28.57%, 19.05%, and 38.09%, respectively. ③ Economic activities were the common driving factors for carbon emissions in all cities, whereas energy consumption and lifestyle were the core driving factors for carbon emissions in resource-dependent cities and traditional industrial cities. After the proposal of Carbon Peak and Carbon Neutrality, energy composition became a key driving force for demonstration cities and emission-reducing cities.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1482-1491"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Distributions and Driving Factors of Hydrochemical Compositions in Different Types of Karst Groundwater in Qingjiang River Basin].","authors":"Hao Xie, Hao-Yong Shen, Hai-Dao Zhang, Yong-Sheng Lin, Jun Li, Hui-Ya Liang, Zhi-Heng Wang, Tian-Long Zhu, Sheng-Zhang Zou","doi":"10.13227/j.hjkx.202401091","DOIUrl":"https://doi.org/10.13227/j.hjkx.202401091","url":null,"abstract":"<p><p>The karst groundwater resource is the key water supply for native residents and industrial and agricultural production in karst regions of southwest China and is even the only water supply for rural regions. Understanding the formation mechanism of hydrochemical compositions is practically imperative to the sustainable development and utilization of karst groundwater resources. The hydrochemical ions of 34 karst spring samples and 12 underground river water samples from the Qingjiang River Basin were measured and analyzed in this study. On the basis of investigating the distribution characteristics of hydrochemical components, methods such as hierarchical clustering analysis, Gibbs model, and relationships between hydrochemical components were used to comprehensively reveal the chemical genesis mechanism of karst groundwater from the perspectives of water-rock interaction and anthropogenic activities, especially in the disturbance mechanism of acidic pollutants on the natural dissolution of carbonate rocks. The results showed that the karst groundwater in the Qingjiang River Basin was weakly alkaline （7.12 ≤pH ≤ 8.69）, and the overall water quality was good. Only the maximum concentration of NO₃^- in the karst spring （80.2 mg·L^-1） exceeded the maximum acceptable limit for drinking purposes （10 mg·L^-1 as N）. The Ca²⁺ and HCO₃^- were identified as the dominant ions, associated with the main water phrase of HCO₃-Ca·Mg in approximately 97.1% of karst spring samples and all underground river water samples. The dominant ions were derived from the strong dissolution of calcite, whereas Mg²⁺、SO₄^2-, and F^- were controlled by the weak dissolution of dolomite, gypsum, and fluorite, respectively. Karst groundwater NO₃^- was derived from the agricultural fertilizers and rainwater input, whereas the H₂SO₄ acid rain input was identified as another important source of karst groundwater SO₄^2-. In addition, the carbonate rocks in the study area were mainly naturally dissolved； however, the input of exogenous acid by humans has changed the original karst hydrogeochemical evolution process and further decreased the carbonate sink flux of karst aquifers, accelerated the decrease rate of karst groundwater table, and increased the pollution risks of karst groundwater.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1417-1426"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Immobilization of Heavy Metals in Municipal Sludge by Co-pyrolysis of Shaddock Peel and Sludge].","authors":"Xiao-Fang Shen, Xin-Yan Gong, Xian Yuan, Qing-Hua Li","doi":"10.13227/j.hjkx.202312034","DOIUrl":"https://doi.org/10.13227/j.hjkx.202312034","url":null,"abstract":"<p><p>Co-pyrolysis with other biomass is a promising method for municipal sludge treatment and has attracted great attention. However, the dominant mechanism by which the heavy metals in municipal sludge are immobilized during the co-pyrolysis remains unknown. In this study, municipal-sludge biochar was prepared by pyrolysis and co-pyrolysis, and the effects of pyrolysis temperature （400-800 ℃） and the addition of shaddock peel on the properties of biochar, the contents of heavy metals （Cu, Zn, Pb, Cd, Ni, and Cr）, and their environmental risks were investigated. Based on the analysis of characterization results and heavy metal contents in the biochar, it was observed that co-pyrolysis promoted the formation of stabilized crystalline minerals （e.g., CdPbO₃, Pb₅（PO₄）₃OH, CuCl, and ZnS）, which reduced the potential risk of heavy metals in biochar. Furthermore, aromatic groups were detected and could interact with heavy metals through cation-π interaction. Further analysis revealed that the immobilization was enhanced by the complexation between heavy metals and the functional groups in biochar, such as -OH and -CO-NH-, which played the main role in the stabilization of Cu and Ni at low pyrolysis temperatures. However, surface sorption and pore filling, due to the increase in specific surface area and porosity, dominated the immobilization of Cd, Cr, Pb, and Zn. The leaching concentrations of heavy metals in co-pyrolysis biochar were much lower than the limit values of \"Identification Standards for Hazardous Wastes-Identification for Extraction Toxicity\" （GB 5085.2-2007） and those by US EPA 1311, 1990. Additionally, the potential ecological risk index （RI value） of heavy metals in biochar was significantly reduced by co-pyrolysis compared to that of sludge or biochar without the co-pyrolysis. This study reveals the dominant immobilization mechanism for specific heavy metals during co-pyrolysis of municipal sludge with shaddock peel and provides an alternative practical strategy for the safe disposal of municipal sludge and biomass wastes.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 2","pages":"944-955"},"PeriodicalIF":0.0,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143441430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}